A stairway is an architectural construction designed to bridge a large vertical distance by dividing it into smaller vertical distances, called steps. For example, a stairway having many steps is used to allow people to easily walk between the floors of a building. Sometimes a stairway is constructed outdoors to allow people to ascend or descend various levels of a local terrain.
A stringer is a structural member that supports the treads and risers in a standard stairway. There are typically three stringers used; one on either side of the stairway and one in the center, with more added as necessary for wider spans. Typically, the stringers extend for the entire length of the stairway and are carefully installed to support the entire weight of the stairway and the people on the stairway. The stringers also determine the angle or level of the treads. Thus, installing stairway stringers requires planning and potentially costly construction depending on the length of the stairway.
Stringer design and installation may be even more complicated and expensive for outdoor stairways. One reason for this is that the outdoor stairway may be longer, and the grade or incline of the terrain may change over the length of the stairway. In this case, additional excavation and structural supports may be necessary. Thus, given the dimensions of the stairway, changing slope or incline of the terrain, and composition of the terrain, an outdoor stairway may be expensive and difficult to construct.
Therefore, it would be desirable to have a way to construct an outdoor stairway that is easier to design and less expensive to install when compared with typical stairways.